This invention relates to the field of percussive tools used in drilling. More specifically, the invention relates to the field of downhole jack hammers which may be actuated by the drilling fluid. Typically, traditional percussion bits are activated through a pneumonic actuator. Through this percussion, the drill string is able to more effectively apply drilling power to the formation, thus aiding penetration into the formation.
The prior art has addressed the operation of a downhole hammer actuated by drilling mud. Such operations have been addressed in the U.S. Pat. No. 4,819,745 to Walter, which is herein incorporated by reference for all that it contains. The '745 patent discloses a simple and economical device placed in a drill string to provide a pulsating flow of the pressurized drilling fluid to the jets of the drill bit to enhance chip removal and provide a vibrating action in the drill bit itself thereby to provide a more efficient and effective drilling operation.
U.S. Pat. No. 6,588,518 to Eddison, which is herein incorporated by reference for all that it contains, discloses a downhole drilling method comprising producing pressure pulses in drilling fluid using measurement-while-drilling (MWD) apparatus and allowing the pressure pulses to act upon a pressure responsive device to create an impulse force on a portion of the drill string.
U.S. Pat. No. 4,890,682 to Worrall, et al., which is herein incorporated by reference for all that it contains, discloses a jarring apparatus provided for vibrating a pipe string in a borehole. The apparatus thereto generates at a downhole location longitudinal vibrations in the pipe string in response to flow of fluid through the interior of said string.